The invention concerns a turnbuckle device for mutually clamping two concrete shell elements comprising a frame with longitudinal struts and transverse struts, across a joint covered by the turnbuckle device formed with claws, wherein the turnbuckle device comprises one or more retaining means for retention on longitudinal or transverse struts of a concrete shell element, by which the turnbuckle device can be mounted on the concrete shell element in a way it cannot fall off self-actingly, preferably also in a position in which the turnbuckle device is positioned within an outer edge of the concrete shell element, and wherein at least one arresting means is provided, wherein the turnbuckle device can be brought into a tensioning position on the concrete shell element when the arresting means is released or removed.
Turnbuckle devices of this type are known e.g. from the document U.S. Pat. No. 3,550,898.
The turnbuckle device disclosed in DE 35 46 832 C2 for mutually clamping two concrete shell elements comprising a frame and a shell cover mounted thereto, along a joint covered by the turnbuckle device, has two principally xe2x80x9cLxe2x80x9d-shaped claws which are disposed next to each other. One kind of the legs of the claws engage behind one abutment surface each of each shell element. The other kind of legs of the claws extend next to each other on the surface of the frame legs facing away from the shell cover. A clamping means engages on these legs. The surfaces of the longitudinal struts facing away from the shell cover abut on said leg of said claw. The other claw is pivotable about an imaginary axis which extends parallel to the joint between the two shell elements to be clamped with respect to each other, and to the shell plane and can be displaced with respect to the one claw at a right angle to the shell plane.
DE29 08 339 C2 discloses a wedging for shell panels for concrete walls, wherein the wedge slide has a substantially U-shaped cross-section comprising legs with inwardly protruding projections which form, with the laterally projecting parts on the transverse strut, a wedging. The transverse strut is lower by the thickness of the yoke part of the wedge slide than the longitudinal struts. A support is provided in the region of the connecting rod on the transverse strut whose height corresponds to this size such that the wedge slide can be retained in the position in which it does not project over the area of the frame.
U.S. Pat. No. 3,550,989 discloses a turnbuckle device for mutually clamping two concrete shell elements which comprise a frame with transverse struts. The turnbuckle device comprises a first and a second lock part, wherein the first lock part can be axially displaced relative to the second lock part. The two lock parts can be pivoted in total about a bolt. The claw of the first lock part is retained on a first concrete shell element via a bolt, whereas the claw of the second lock part can engage a bolt of a second concrete shell element. For arresting the turnbuckle device, an arresting means is provided which can limit the pivoting range of the entire turnbuckle device when the claw of the second lock part abuts the bolt of the second concrete shell element. The arresting means permits mutual clamping of the lock parts.
It is the underlying purpose of the invention to produce a turnbuckle device which on the one hand can be mounted to any point of the transverse struts and/or longitudinal struts of a concrete shell element and on the other hand can remain at the mounted point for removing a concrete shell element and, in use, can compensate for a level difference between two concrete shell elements.
This object is achieved in accordance with the invention in that the turnbuckle device comprises a second lock part which can be pivoted relative to the first lock part, wherein the first lock part comprises a stationary first claw and the second lock part comprises a second claw, with both claws being adjusted to be suitable for direct engagement on the frame, wherein the arresting means limits the pivoting range of the second lock part such that the second claw prevents release of the turnbuckle device from the concrete shell element and optionally limits or prevents movability of the turnbuckle device on the frame section.
The inventive turnbuckle device permits on the one hand to mutually clamp concrete shell elements in a conventional fashion, and, on the other hand, the turnbuckle device can be left on one of the concrete shell elements when the concrete shell elements are to be moved at a building site. Towards this end, the inventive device is moved and positionally fixed in a region in which it no longer protrudes over the edge of a concrete shell element. No additional means are required to displace and fix the inventive turnbuckle device. Merely the clamping connection known to the skilled worker must be released with conventional means. When the clamping connection is released, part of the inventive turnbuckle device can be pivoted and be displaced until it is located within a concrete shell element. In this position, the pivotable part of the inventive turnbuckle device can be pivoted back into a closed position in which a stationary part of the inventive turnbuckle device is oriented corresponding to the pivotable part along a transverse or longitudinal strut. The pivotable part can be blocked by the clamping means, e.g. a wedge. Retaining means retain the stationary part of the inventive turnbuckle device at the concrete shell element to exclude accidental drop or detachment of the inventive turnbuckle device when moving a concrete shell element, e.g. with a crane.
The inventive turnbuckle device allows the construction of large shell surfaces in less time and in a simpler way. When the inventive turnbuckle device is unlocked and mounted to the concrete shell element via retaining means, it can be displaced with one hand in a controlled fashion without being removed from the concrete shell element, and the clamping means can be activated or released with the other hand, if required. The skilled worker does not have to hold the weight of the inventive turnbuckle device since it is guided and displaceably supported on the transverse or longitudinal strut. This facilitates the handling of the inventive turnbuckle device and the effort required for alignment, release or clamping of the turnbuckle device.
Recesses can be provided along the longitudinal or transverse struts of the concrete shell elements behind which the one or more retaining means can engage, wherein the recesses are formed in the surface and/or the side faces of the longitudinal and/or transverse struts.
This is advantageous in that the inventive turnbuckle device can be displaceably mounted on the concrete shell element with simple means that cannot fall off self-actingly. The recesses can extend over the entire length of the frame legs or the transverse struts. This design permits displacement of the inventive turnbuckle devices within a wide region on the concrete shell element without a need for dispensing with a secure holding of the turnbuckle device on the concrete shell element. The turnbuckle device can be safely mounted with retaining means, such as archings or bolts on the concrete shell element via openings or simple profilings or grooves on the longitudinal or transverse struts.
In an advantageous fashion, the turnbuckle device can be removed from the concrete shell element when the arresting means is released or removed.
A particular holder with the most simple means which safely holds and guides the inventive turnbuckle device is provided when the retaining means are archings which protrude locally from the inner surface of the stationary claws and engage in lateral recesses of the longitudinal or transverse strut. Such archings can be produced without additional material by pressing out of the claw material, or bolt-like projections are mounted at appropriate points on the inner surfaces of the claws. If the opposite archings, bolts, etc. are mutually offset, a separation, i.e. a free length between the archings can be produced via pivoting of the inventive turnbuckle device in the released state, said free length in the pivoted state of the turnbuckle device being larger, with respect to a transverse strut or longitudinal strut, than the width of a longitudinal strut or a transverse strut, and therefore no longer engage in the pivoted state of the longitudinal strut or transverse strut. In this state, pivoted with respect to the axial orientation of the transverse strut or the longitudinal strut, the inventive turnbuckle device can be removed from the transverse strut or from the longitudinal strut. If the turnbuckle device is disposed on the longitudinal strut or the transverse strut and the archings of the turnbuckle device engage behind the transverse strut or the longitudinal strut, the archings are disposed such that they are guided with play in the recesses of the longitudinal strut or the transverse strut. This facilitates displacement of the turnbuckle device along a longitudinal strut or a transverse strut.
In a further embodiment of the invention, the archings can be formed opposite to each other, and the end regions of the longitudinal struts or transverse struts each comprise recesses with limited length in the edge region in the surface of the longitudinal struts and/or transverse struts, and the size (length, width, height) of the recesses are matched to the position of the archings such that the turnbuckle device is held within a concrete shell element when the second claw is in the pivoted inner position state. If the archings are directly opposite to each other, the turnbuckle device must be mounted into a recess, e.g. a groove, of a longitudinal strut or a transverse strut by opening the turnbuckle device that wide that the pivotable claws do not obstruct mounting of the turnbuckle device. The size and shape of the stationary and pivotable claws permit matching of the size of the recesses to the turnbuckle device such that in the pivoted inner position state of the turnbuckle device, the turnbuckle device cannot inadvertently slide through the recesses out of the transverse strut or longitudinal strut and drop off from the concrete shell element.
In a further embodiment of the inventive turnbuckle device, the retaining means is formed by a shackle which projects from a rod-shaped body which holds the first lock part and movably guides it on the concrete shell element. The turnbuckle device is detachably held on the concrete shell element via a mounting means, e.g. a bolt, in that the bolt is put through a first opening in the shackle and at the same time through a second opening in the longitudinal strut or in the transverse strut. The turnbuckle device can be displaced along the rod-shaped body in the unlocked state, and a pivoting motion of part of the inventive turnbuckle device with respect to the stationary part of the turnbuckle device is not impaired by the rod-shaped body. The bolt can also be formed on the shackle in accordance with the invention. The bolt can engage in openings on the concrete shell element and may be secured, if required.
The inventive turnbuckle device can be pivoted via engagement of the bolt on the concrete shell element, if required, wherein the bolt forms the axis of rotation. In such an embodiment, the pivoting range of the movable claw can be reduced and the advantages with regard to handling and safety of the inventive turnbuckle device can still be achieved without any limitations.
In a further embodiment of the invention, the retaining means is formed by a pivoting and/or tilting lever which is provided on the stationary claws or in the region of the stationary claws, wherein the pivoting and/or tilting lever engages behind surfaces of the longitudinal or transverse struts, when connected to a longitudinal or transverse strut.
This is advantageous in that such retaining means can be mounted to any recesses of a longitudinal or transverse strut. The pivoting and/or tilting levers can be disposed on a claw itself or directly behind a stationary claw. The pivoting and/or tilting levers can be fixed in position either through spring elements or latches to provide secure retention of an inventive turnbuckle device on a concrete shell element. In order to suspend the connection to a longitudinal or transverse strut, latching of the pivoting and/or tilting levers must be released or a spring-loaded pivoting or tilting lever must be released from the spring load. Such a retaining means provides a simple and quick to handle connecting system for a turnbuckle device to be detachably mounted to a concrete shell element.
In a particularly advantageous manner, the arresting means is a wedge which blocks the pivotable claw in the pivoted inner position state or clamps the turnbuckle device for mutually clamping two concrete shell elements when the wedge is displaced in the direction of the acting force of gravity on horizontally oriented struts. If the wedge is displaced against the force of gravity, the second claw can be pivoted into an open position and a displacing position. In the open position, the pivotable claw can be pushed towards the stationary claw until both claws, the stationary and the pivotable claw, can abut within one concrete shell element. The claws can be mutually fixed via the arresting means, e.g. a wedge, thereby preventing that the turnbuckle device twists with respect to the transverse strut or longitudinal strut or is displaced into a position in which the turnbuckle device could project over the edge of a concrete shell element.
If the inventive turnbuckle device is mounted to vertically oriented struts, the arresting means, e.g. a wedge, must be displaced such that it exerts the same function as in the above description.
Further advantages can be extracted from the description and the enclosed drawing.